As part of the general cleanup of the repository to put all platform build tooling into the Platforms folder, we need to move the Apple folder to Platforms/Apple.

This is also an opportunity to clean up the legacy iOS folder, which only exists for historical buildbot compatibility.

Linked PRs

• gh-146444: Move the Apple folder to the Platforms directory #146497
• gh-146444: Make Platforms/Apple/ compatible with Python 3.9 #146624
• [3.14] gh-146444: Make Platforms/Apple/ compatible with Python 3.9 (GH-146624) #146627
• gh-146444: Don't package as part of iOS 'build hosts' target #146628
• [3.14] gh-146444: Don't package as part of iOS 'build hosts' target (GH-146628) #146629
• gh-146444: Remove legacy iOS folder #147993